Helmets for various activities, including sporting activities and work in dangerous environments, often require a shell or protective surface. The range of shapes and sizes of a wearer's head may require a helmet to be made larger or smaller to fit. Furthermore, adjustment may be required depending on the activity, environmental conditions, appearance, or some other factor. In particular, the wearer of a helmet may want to have a tighter or looser fit, depending on circumstances, or may alternatively want to modify the fit, for example during play, or depending on the season, etc.
Adjustable helmets typically include two sections that are moved to lengthen the helmet. For example, U.S. Pat. No. 4,477,929 to Mattsson discloses an adjustable helmet wherein adjustment typically requires the use of a screwdriver to tighten and loosen a screw. Loosening of the screw permits the helmet to be adjusted, and tightening of the screw maintains the helmet in a particular configuration. This requirement for additional tools to adjust the helmet may make it difficult to adjust the helmet when proper tools are not available. Other helmets known in the art also have limitations making them difficult or otherwise inconvenient to use.
Accordingly, there is a need for alternative helmets.